LOS ANGELES, CALIFORNIA—Neurobiologist Caleb Finch of the University of Southern California used CT scanning technology to examine the arteries of mummies from five different archaeological sites spanning 4,000 years. The Peruvian, ancestral Pueblo Indian, indigenous Aleutian islander, and ancient Egyptian populations that he tested showed signs of atherosclerosis, or narrowing of the arteries. The fats and sugars of the modern diet are known to contribute to clogged arteries and heart disease, but “the generality of our observations suggests it is really a basic part of human aging under all circumstances,” he said.